This gets the local host's public IP info:
$ curl -L q.dynaip.net
{"timezone":"America\/New_York","isp":"Lightstream Transmission and Telecom Inc","region_code":"GA","country":"United States","dma_code":"0","area_code":"0","region":"Georgia","ip":"199.233..","asn":"AS7363","continent_code":"NA","city":"Atlanta","postal_code":"30303","longitude":-84.3915,"latitude":33.7516,"country_code":"US","country_code3":"USA"}
This gets any IP info you want, for example, 8.8.4.4,
$ curl -L q.dynaip.net/8.8.4.4
{"country":"United States","dma_code":"0","area_code":"0","ip":"8.8.4.4","asn":"AS15169","continent_code":"NA","isp":"Google Inc.","longitude":-97,"latitude":38,"country_code":"US","country_code3":"USA"}
Maybe you somebody else has known that, but I found it's useful for me. :p